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<!--压缩文件jar包-->
<dependency>
<groupId>ant</groupId>
<artifactId>ant</artifactId>
<version>1.6.5</version>
</dependency>
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.io.File;
import java.io.InputStream;
import java.util.Enumeration;
import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipFile;
/*
* -Xms2048m -Xmx2048m 大文件解析推荐设置JVM大小 否则解压文件内存溢出
传统IO 在读取超过100M的文件 性能很低
* */
public class NIOReader {
private static final String CHARSET = "GBK";
public static void main(String args[]) throws Exception {
File file2 = new File("D:\\1.txt");//读取的文件
List<String[]> list2=read(file2);
for(String[] s:list2){
String tmp = Arrays.toString(s);
System.out.println(tmp);
}
}
public static List<String[]> read(File file) {
List<String[]> list = new ArrayList<String[]>();
int bufferSize = 1000000;//一次读取的字节长度
FileChannel fileChannel = null;
try{
fileChannel = new RandomAccessFile(file, "r").getChannel();
}catch(Exception e){
e.printStackTrace();
}
ByteBuffer readBuffer = ByteBuffer.allocate(bufferSize);
byte[] lineByte = new byte[0];
try {
//temp：由于是按固定字节读取，在一次读取中，第一行和最后一行经常是不完整的行，因此定义此变量来存储上次的最后一行和这次的第一行的内容，
//并将之连接成完成的一行，否则会出现汉字被拆分成2个字节，并被提前转换成字符串而乱码的问题
byte[] temp = new byte[0];
while (fileChannel.read(readBuffer) != -1) {//fileChannel.read(readBuffer)：从文件管道读取内容到缓冲区(readBuffer)
int readSize = readBuffer.position();//读取结束后的位置，相当于读取的长度
byte[] byteArray = new byte[readSize];//用来存放读取的内容的数组
readBuffer.rewind();//将position设回0,所以你可以重读Buffer中的所有数据,此处如果不设置,无法使用下面的get方法
readBuffer.get(byteArray);//相当于rBuffer.get(bs,0,bs.length())：从position初始位置开始相对读,读bs.length个byte,并写入bs[0]到bs[bs.length-1]的区域
readBuffer.clear();
int startNum = 0;
int LF = 10;//换行符
int CR = 13;//回车符
boolean hasLF = false;//是否有换行符
for (int i = 0; i < readSize; i++) {
if (byteArray[i] == LF) {
hasLF = true;
int tempNum = temp.length;
int lineNum = i - startNum;
lineByte = new byte[tempNum + lineNum];//数组大小已经去掉换行符
System.arraycopy(temp, 0, lineByte, 0, tempNum);//填充了lineByte[0]~lineByte[tempNum-1]
temp = new byte[0];
System.arraycopy(byteArray, startNum, lineByte, tempNum, lineNum);//填充lineByte[tempNum]~lineByte[tempNum+lineNum-1]
String line = new String(lineByte, 0, lineByte.length, CHARSET);//一行完整的字符串(过滤了换行和回车)
list.add(line.split("\t"));
//过滤回车符和换行符
if (i + 1 < readSize && byteArray[i + 1] == CR) {
startNum = i + 2;
} else {
startNum = i + 1;
}
}
}
if (hasLF) {
temp = new byte[byteArray.length - startNum];
System.arraycopy(byteArray, startNum, temp, 0, temp.length);
} else {//兼容单次读取的内容不足一行的情况
byte[] toTemp = new byte[temp.length + byteArray.length];
System.arraycopy(temp, 0, toTemp, 0, temp.length);
System.arraycopy(byteArray, 0, toTemp, temp.length, byteArray.length);
temp = toTemp;
}
}
if (temp.length > 0) {//兼容文件最后一行没有换行的情况
String line = new String(temp, 0, temp.length, CHARSET);
list.add(line.split("\t"));
if (!line.contains("\t")) {
System.out.println(line);
}
}
} catch (IOException e) {
e.printStackTrace();
}
return list;
}
public static List<String[]> readZip(String fileName) {
List<String[]> list = new ArrayList<String[]>();
List<File> fileList= unZip(fileName);
//每一份文件的表头没有被删除 包含在内
for(File file :fileList){
System.out.println(file.getAbsolutePath());
List<String[]> tmpList = read(file);
list.addAll(0, tmpList);
}
//上传的文件保存在service\target\classes\201901.txt
//文件解压以后先删除所有解压后的txt文件 然后删除父类文件夹 zip源文件导入成功后删除
File parentFile = null;
for(int i =0;i<fileList.size();i++){
File file = fileList.get(i);
if(i==fileList.size()-1){
parentFile=file.getParentFile();
}
file.deleteOnExit();
}
parentFile.deleteOnExit();
return list;
}
//解压指定zip文件 获取解压后的文件路径
public static List<File> unZip(String str) {//unZipfileName需要解压的zip文件名
List<File> list = new ArrayList<File>();
FileOutputStream fos;
File file;
InputStream inputStream;
try {
ZipFile zipFile = new ZipFile(new File(str), "GBK");
for (Enumeration<ZipEntry> entries = zipFile.getEntries(); entries.hasMoreElements(); ) {
ZipEntry entry = (ZipEntry) entries.nextElement();
String tmp = str.substring(0, str.lastIndexOf("."));
if (!new File(tmp).exists()) {
new File(tmp).mkdirs();
}
file = new File(tmp + File.separator + entry.getName());
if (entry.isDirectory()) {
file.mkdirs();
} else {
//如果指定文件的目录不存在,则创建之.
File parent = new File(file.getParent());
if (!parent.exists()) {
parent.mkdirs();
}
inputStream = zipFile.getInputStream(entry);
fos = new FileOutputStream(file);
int readBytes=0;
byte[] buf = new byte[1024 * 1024 * 1024];
while ((readBytes = inputStream.read(buf)) > 0) {
fos.write(buf, 0, readBytes);
}
fos.close();
inputStream.close();
}
list.add(file);
}
zipFile.close();
} catch (IOException ioe) {
ioe.printStackTrace();
}
return list;
}
}